Mineral oil composition



Patented Jan. 21, 1936 25.328157 UNITED STATES PATENT OFFICER g mamas-l 1 Q menu. on. com-osmon Bertrand W. Story, Paulsboro, and Everett W.

Fuller, Woodbury, N. 1., assignors to Soconir- Vacuum Corporation, New York, N. Y., a corporation of New York No Drawing; Application September 1, 19:3,

, Serial No. 688,436

1 Claim. (cl. 117-0) This invention relates to the improvement of were tested, after the indicated time intervals, viscous oils, such as turbine oils andjnsulating for Lovibond color and neutralization number. oils, which have been highly refined, as by the Example 1.Transformer oil, consisting of use of large q a t of sulphuric acid. includ- Coastal distillate treated with 50 lbs. or 98% ing fuming acid. Suchhighly refined oils are sulphuric acid and 200 lbs. of 104% sulphuric 5 susceptible, under the elevated temperatures enacid per barrel of 11, neutralized t sodium countered in their use, to atmospheric oxidation hydroxide and filtered through fuuers earth Its resulting particularly in the formation of color- 001017, Lovibond, was less t 0.1 specific graving matter and acid. The purpose oi the invenit 0370. $0051 s 01 umver o tion is to produce compositions, ifor such oils, in y vi y t Sal at 10 which such color and acid formation is greatly 69 Seconds reduced or substantially inhibited.

In our application for Letters Patent of the 81mm 192mm United States, filed June 10, 1931, Serial No. Timmmemu with 543,396, we have disclosed the discovery that (11- C010, $32 0010, A l lld 15 benzyl disulfide has the capability oi inhibiting, to a large extent, the formation of acid in highly refined oils when dissolved therein in small quaninhibit 3:3 a 5 0 titles. In his application for Letters Patent of a0 ofzs 20 the United States filed February 16, 1933, Serial 6 M5 2 No. 657,106, the applicant Fuller has shown that 0.0l0%2.2'dihydroxr1.1' in n the monosulfides of hydroxy aromatic compounds 5% figgg 'agg ay g 10-00 have the same capability. We have now dis amw z z' i v r xy 1.1 dicovered that the use, in combination with di-- y sumd" benzyl disulfide of a monosulfide of a hydroxy- 26 aromatic compound results in the inhibition of Example g n Coastal distillate color and acid formation, in highly refined 50 lbs. of 98% and 100 lbs. of' 104% sulphuric cons oils to a degree much beyfmd that which acid, neutralized and filtered, color less than 0.1; can be attained by the use of either stabilizing specific gravity 0376; viscosity at F" 56 sec 30 body alone in its optimum quantity. As an ex- 30 ample, taken from the results hereinafter tabu- 48h 96h lated, it has been iound that in a given 011 subjected to an oxidation test, in the presence 01 Transiormer oil with copper foil, for 96 hours, the acid value, (neu- -Col- $3? 001- g? Col- $2,) tralization number), using 0.05% of dibenzyl diue ue no 35 sulfide alone, was 0.13, and using 0.010% of monosulfide of m-cresol, was 6.05. By the use of 0.05% No inhibitor 11 mm o! dibenzyl disulfide, together with either 0.010% benzy1disu1fl 13 0.13 23 0.22 or 0.005% of monosulfide of m-cresol, the acid 3;},3Z' %fi;21 40 value was reduced to 0.02; that is, to less than in phthrl I 5.3 10.10 40 one sixth of that occurring with the dibenzyl di- ,,i;fi,;,%'f 8.5 0.05 sulfide alone, and less than one three-hundredth dibenzy 9181511 00 or that occurring with the monosulfide or m- 12, ig i ii cresol alone. The color, with the dibenzyl disul- M4 14 46 fide alone, was 13 and with the 0.10% or mono- 3523i f 14 0.00

sulfide or m-cresol alone it was 14, but with the "-"gfi g gg g mgg two materials used together the color was reduced 0! me a? 2.0 0.02 0 0.00 o1. wearers:

We give hereinafter, in tabular form, the reelm-cresol L5 -02 suits of tests 01' dibenzyl disulfide and of various mum-nae of thy- 1.1 0.02 is 10.20 50 mo'nosulfides oi hydroxy aromatic compounds, in 1 g Pi'jg gfggfi various quantities and for various-periods, both gggmlg 1 mad 1 0.08 11 0.1a alone and in combination. f, sat. 3 6 In each of the tests in question a 200 gram sam- 31, g diphanyl 1 7 o 02 4 0 m 55 ple of the oil, containing a piece of freshly polished copper foil 40 x x 0.1 millimeters in size, was maintained at a temperature of C. while x mp -Tllr in oil treated with 50 lbs. oxygen gas was bubbled through it at the rate of 98% and lbs. of 104% sulphuric acid per 60 o! 2, ml. per hour. 10 sampl s 1 the oil barrel 01 oil, neutralized and filtered. Color, less 00 v than 0.1; specific gravity, 0.862; viscosity at 100 F., 122 sec.

We have found that, in general, the optimum quantity of dibenzyl dis'ulfide for stabilizing a highly refined viscous oil against color and acid formation is approximately 0.10% by weight or less, that is, that the use of any larger quantity imparts little or no greater stability to the oil. In the case of the hydroxy-aromatic monosulfides, the optimum quantity is usually between 0.005% and 0.010%. It is evident, therefore, that the disproportionate result secured by the combined use of the two constituents in their optimum quantities or less, is due not to an increase in the total quantity of inhibiting material, but

to some interaction or action in combination of the constituents.

In the aforesaid application, Serial No. 543,396

we have disclosed compounds, are efiective as stabilizers of highly refined viscous oils. Our experiments have indicated, however, that such disulfides do not have, in general, the peculiar cooperative relation with the hydroxy-aromatic monosulfides herein set forth. So far as we have ascertained, it is only in the case of dibenzyl disulflde-that any notable increase in stabilization is secured by the inclusion of a hydroxy-aromatic monosulfide.

It will be understood that when we refer to a highly refined oil we intend an oil, however pro- BERTRAND W. STORY. EVERETT W. FULLER.

that thedisulfides of organic I compounds in general, and particularly of dialkyl 

